SCIENCE

Detecting Drool: A fresh look at identifying oral fluid stains on fabrics

Sat Feb 01 2025
For a long time, DNA has been like the superhero of crime scene investigations But guess what? Too much evidence can overwhelm crime labs and create huge backlogs making this investigation process lengthy Moreover, many pieces of evidence at crime scenes can be body fluids. Oral fluid stains are one of these fluids that can be found on various surfaces, allowing forensic scientists to identify individuals who left traces Can you imagine bringing a murderer to justice with just a bit of spit on a cloth? That is the power of forensic science. Samples of oral Fluid could be found on all sorts of materials, from common cotton to polyester, and especially jeans which can be more difficult. So, researchers had an idea: use special technology to spot oral fluid stains quickly and non-destructively. This way, crime labs can skip the irrelevant samples and focus on the good stuff. This is where Deep-UV Raman spectroscopy comes in. It's like a super-sniffer for detecting oral fluid stains on different fabrics. Unlike Near IR it detects the stain without any destructive sampling first. This special tool uses deep ultraviolet light to figure out what's in a sample. Near-IR is used in conventional spectroscopy. Every material has a unique Raman Spectra. The results can then be compared using statistical analysis. Deep-UV Raman spectroscopy is definitely faster and gives clearer readings. Think about it: If an oral fluid stain is found on a suspects clothing and can be identified as saliva if it is compared to a known sample,this can make the lab process much faster. It would do wonders for DNA phenotyping and improve theperformance of the forensic labs. This would keep lab researchers from wasting time on irrelevant samples. Statement of fact: We all have unique saliva. This is great for forensic purposes. By using this technique, forensic scientists canquickly identify whether a stain is actually oral fluid or not. It's like having a secret decoder ring for crime scenes. The best part? It doesn't require much sample preparation, so it's faster and less complicated. The technique could actually be available for use in the near future This brings us to an important question: Why haven't we been using this cool technology all along? Because there are many other processes currently being used. Anyway, this study shows that deep-UV Raman spectroscopy could be a significant improvement for these types of investigations.

questions

    How does deep-UV Raman spectroscopy compare to other existing methods in terms of cost-effectiveness and accessibility for forensic laboratories?
    Could it be possible that the technology described in the article is being secretly used by law enforcement to profile and target individuals without their knowledge?
    How does the accuracy of deep-UV Raman spectroscopy vary with the age and degradation of the oral fluid stains on fabrics, especially stains that affected by factors such as environment or allergic flushes that could affect the DNA from the oral fluid evidence?

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